Seagen Inc. and Astellas Pharma Inc. announced that patient enrollment was completed in Cohort K of the phase 1b/2 EV-103 clinical trial (also known as KEYNOTE-869). The cohort is evaluating PADCEV (enfortumab vedotin-ejfv) in combination with Merck's anti-PD-1 therapy KEYTRUDA (pembrolizumab) as first-line treatment in patients with unresectable locally advanced or metastatic urothelial cancer who are unable to receive cisplatin-based chemotherapy in the first-line setting. Merck is known as MSD outside the United States and Canada.

EV-103 is a multi-cohort, open-label, multicenter phase 1b/2 trial of PADCEV alone or in combination, evaluating safety, tolerability and efficacy in muscle invasive bladder cancer and in locally advanced or metastatic urothelial cancer in first- or second-line settings. Key outcome measures of EV-103 Cohort K are objective response rate (ORR) per blinded independent central review (BICR) using RECIST 1.1 and duration of response (DoR). The U.S. Food and Drug Administration (FDA) granted Breakthrough Therapy designation in February 2020 for PADCEV in combination with KEYTRUDA for patients with unresectable locally advanced or metastatic urothelial cancer who are unable to receive cisplatin-based chemotherapy in the first-line setting.

The designation is based on results from the dose-escalation cohort and expansion cohort A of the EV-103 trial.